This invention relates generally to methods and apparatus for review of medical imaging exams, and more particularly to methods and apparatus for review of computed tomographic (CT) colonography and lung exams.
CT imaging provides a description of anatomy in great detail and is therefore being increasingly used for detecting and following the evolution of lesions that may be potential cancers. Radiologists search for nodules and polyps in the lung and colon using advanced lung analysis (ALA) and Computed tomographic colonography (CTC). Lung Cancer and Colon Cancer are the first and third leading cause of cancer related mortality in the US with estimated 175,000 and 57,000 deaths in 2003. Many references in the literature point to better patient management from earlier detection.
Radiologists currently detect nodules in the lung by viewing the axial slices of the chest. This is time consuming and is getting more so with the resolution increase and hence the explosion of the amount of CT slices to be reviewed. For lung CT, detection is followed by an analysis for characterization of the nodule with the help of ALA's segmentation, volume measurement and reporting tools. During some of reader studies considerable variability in the detection of small nodules in lung scans by expert radiologists was found. In addition there are similar studies in the literature that describe a sensitivity issue when detecting nodules. Similar studies show reader variability in detecting polyps. Co-pending patent application Ser. No. 10/756,872 filed Jan. 12, 2004 (hereby incorporated in its entirety) describes using shape overlay information on the virtually dissected colon has been submitted to address better visualization of the colonic polyps. Another co-pending patent application Ser. No. 10/709,355 filed Apr. 29, 2004 (also hereby incorporated in its entirety) provides a real-time 3D shape filtering method to enhance certain geometrical features. These methods provide complementary shape information that can aid in the diagnosis of anatomical and/or clinical conditions. It was noted that providing simple raw results of the shape descriptors tended to overwhelm the user with either fragmented or at times false clinical information. Such information, even though an accurate representation of the filtering, should be presented to the user in a clinically efficient manner.